#define _REENTRANT
#include<stdio.h>
#include<unistd.h>
#include<stdlib.h>
#include<string.h>
#include<pthread.h>
#include<semaphore.h>

sem_t bin_sem;

#define WORK_SIZE 1024
char work_area[WORK_SIZE];

void* thread_function(void* arg)
{
	sem_wait(&bin_sem);
	while (strncmp("end", work_area, 3) != 0)
	{
		printf("You input %ld characters\n", strlen(work_area) - 1);
		sem_wait(&bin_sem);
	}

	pthread_exit(NULL);
}

int main(void)
{
	int res;
	pthread_t a_thread;
	void* thread_result;

	res = sem_init(&bin_sem, 0, 0);
	if (0 != res)
	{
		perror("Semaphore initialization failed");
		exit(EXIT_FAILURE);
	}
	res = pthread_create(&a_thread, NULL, thread_function, NULL);
	if (0 != res)
	{
		perror("Thread creation failed");
		exit(EXIT_FAILURE);
	}

	printf("Input some text. Enter 'end' to finish\n");
	while (strncmp("end", work_area, 3) != 0)
	{
		fgets(work_area, WORK_SIZE, stdin);
		sem_post(&bin_sem);
	}

	printf("\nWaitign for thread to finish...\n");
	res = pthread_join(a_thread, &thread_result);
	if (0 != res)
	{
		perror("Thread join failed");
		exit(EXIT_FAILURE);
	}

	printf("Thread joined\n");
	sem_destroy(&bin_sem);
	
	return 0;
}
